Lentils, like other legumes, are perhaps the best food source of slowly-digested carbohydrate and resistant starch. Essentially, this means that they contain starch which is slowly converted to glucose, and starch which is not digested in the small intestine at all. At least one study has shown that replacing more rapidly-digested carbohydrates with legumes improved glycemic control in diabetics. Consuming foods high in resistant starch may also improve colon health, including promoting healthy bowel flora. Resistant starch may even improve insulin sensitivity and absorbtion of minerals such as calcium.